Flashlights are well-known in the prior art and have been heavily utilized in emergency situations and by law enforcement personnel in the execution of their duties. During use, such flashlights may be subjected to harsh environments and treatment. Flashlights should therefore be designed to withstand the application of various forces, such as the force from retracting an expandable baton when attached to such a weapon, impact with the ground if dropped to unholster a weapon, or forces from the recoil of a firearm when attached as a lighting device. In addition, flashlights should withstand the presence of debris, including water and mud, that could interfere with the operation of the flashlight.
Generally, such flashlights include a housing that is formed of a body section and a head section. The head section typically houses a lens, a reflector, and a lamp assembly, all of which are secured in the head section by a lens ring that is threadingly engaged with the head section. The body section houses batteries utilized to energize the lamp and a switch assembly to control the operation of the lamp.
One example of a lamp assembly 10 is shown in FIG. 1 of the present application and discussed in detail in commonly owned U.S. patent application Ser. No. 08/738,858, which is still pending and which is hereby incorporated by reference. The lamp assembly 10 of the flashlight permits for the adjustment of the light beam but prevents the inadvertent displacement of the lamp relative to the reflector.
As shown in FIG. 1, the lamp assembly 10 includes an outer adjustment ring 12, a lamp bulb 14, a bulb shock absorber 16, a circuit board 18, a board containment plate 20, and non-conductive fasteners 22. The outer adjustment ring 12 has a through bore 25 in which is defined a first internal radial shoulder 27 and a second internal radial shoulder 29. Threaded fastener bores 31 are provided on the second radial shoulder 29, extending coaxially with the through bore 25.
The lamp bulb 14 and the bulb shock absorber 16 are mounted on the circuit board 18. In use, all three elements are seated in the through bore 25 of the outer adjustment ring 12, with the circuit board 18 abutting against the second radial shoulder 29. The circuit board 18 is provided with fastener bores 33 that are intended to axially align with the fastener bores 31 of the outer adjustment ring 12.
The board containment plate 20 is disposed adjacent to the circuit board 18 to contain the board 18 within the adjustment ring 12. The plate 20 is provided with an annular shoulder 35 and countersunk bores 36. When disposed to contain board 18, the annular shoulder 35 abuts the first radial shoulder 27 of the ring 12. The bores 36 are intended to align axially with the threaded fastener bores 31 of the adjustment ring 12 and the fastener bores 33 of the board 18. This permits the non-conductive threaded fasteners 22 to extend through the plate 20 and the board 18, and to threadingly engage the threaded fastener bores 31 of ring 12 so that the board 18 is secured within the adjustment ring 12.
Once the board containment plate 20 is disposed adjacent to the circuit board 18 and the fasteners 22 are threaded in place, the o-rings 40 can be mounted on the outer adjustment ring 12, just above the threading 42. The outer adjustment ring 12 is then threadingly engaged to the reflector, which is in turn mounted within the head section of the flashlight.
The lamp assembly 10 of FIG. 1 does have its drawbacks. One such drawback is the difficulty involved in assembly and disassembly. For example, if the circuit board is damaged and requires replacement, the lamp assembly must be taken apart. In order to do so, both the lens ring and the reflector must be removed from the head section of the flashlight. The lamp assembly 10 can then unscrewed from the reflector. Using a tool, both of the threaded fasteners 22 must be unscrewed and removed from the assembly. The removal of the fasteners allows the board containment plate 20 and the circuit board 18, which carries the lamp bulb 14, to be removed from the bore 25 of the outer adjustment ring 12. The lamp bulb 14 can then be detached from the circuit board 18 and the circuit board can be replaced. Once the new circuit board is in place, the above steps are reversed and the assembly 10 is re-assembled.
Such a process may take much time. The size of the threaded fasteners, in particular, makes disassembly awkward. The use of a small screwdriver can be very difficult. Even the use of a tool does not greatly facilitate the removal of the fasteners. Also, it is possible that the fasteners may be lost due to their small size. The loss of these fasteners would hinder the re-assembly of the flashlight.
In addition to being difficult to work with, the fasteners do not have adequate strength. The fasteners are made of a non-conductive material such as nylon. During use of the flashlight, the fasteners sometimes sheer off. To address this problem, the fasteners are fabricated of metal, instead of nylon. The fasteners being constructed of metal, however, necessitate the use of non-conductive insulators. Unfortunately, this change increases the cost of the assembly without solving the strength problem. Even with the metal fasteners, the lamp assembly remains rather weak. Further, the presence of the non-conductive insulators introduces the potential for the screws to short circuit.
Another disadvantage of the lamp assembly 10 is brought about during its manufacture. Certain design features of the assembly 10 add considerably to the time required to manufacture it as well as the difficulty experienced in doing so. For example, the outer adjustment ring 12 requires two distinct internal radial shoulders 27 and 29 to be provided in its through bore 25. Machining such shoulders in the through bore 25 with the requisite dimensional accuracy is both difficult and tedious.
Further, the numerous bores required in the design of this assembly also add to the difficulty experienced during the manufacturing process. Threaded fastener bores 31 must be provided on the second radial shoulder 29 of the outer adjustment ring 12. Also, fastener bores 29 are required on the circuit board 18. In addition, countersunk bores 33 must be provided through the board containment plate 20. The small size of the elements and the dimensional accuracy required of the bores contributes to the difficulty experienced during the manufacturing process. The difficulty experienced during the manufacturing process and the time required to manufacture such an assembly both contribute to the cost of the lamp assembly.
Thus, there is a need in the prior art to provide a lamp assembly that can be quickly and easily disassembled to facilitate the replacement of the elements of the lamp assembly.
There is a further need for a lamp assembly that has the requisite amount of strength to withstand the rigors of use.
There is yet a further need for a lamp assembly that can be easily and accurately manufactured while keeping the manufacturing costs at a minimum.